package main

import (
	"fmt"
	"math"
)

func main() {
	//Dim 返回 x-y 或 0 的最大值。
	//Dim(+Inf, +Inf) = NaN
	//Dim(-Inf, -Inf) = NaN
	//Dim(x, NaN) = Dim(NaN, x) = NaN

	fmt.Printf("%.2f\n", math.Dim(4, -2))
	fmt.Printf("%.2f\n", math.Dim(-4, 2))
	//6.00
	//0.00
}
